On things to fix:

While I appreciate the use of history, I promise you I don't need to hold my position on the page for every single letter I type in the search box: http://screencast.com/t/1qFwxlz5

I ended up with a history entry for "search results for 'c'", "search results for 'co'", "search results for 'cog'", etc.

Maybe trim this down to only firing after 10s on inactivity in a text input or use onblur? I'm not too sure what the answer is but it (page history) definitely loses any usefulness when architected in this manner.